Electric switch



May 27, 1930. J. D. H|| L.|ARD 1,760,554

. ELECTRIC swITcH Filed June 2l, 1926 Inventor:

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Patented May 27, 1930 PATENT ori-ics JOHN D. HILLIARD, OF SCHENECTADY, NEW YRK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEVI YORK ELECTRIC SWITCH Application filed June 21,

My invention relates to electric switches of the fluid-break explosion chamber type.

With this type of switch as commonly constructed, having the fixed contact in the explosion chamber, the pressure of gas produced by the arc in the explosion ychamber as the contacts separate accelerates the opening movement of the switch and also directs a stream of insulating liquid into the arc. In

g. such a switch some gas is also produced when the contacts are brought together to close the circuit and when the switch is called upon to close on a heavy load the quantity of gas suddenly formed in the explosion'chambcr may be sullicient to produce a pressure therein which by opposing the inward movement of the movable contact somewhat interferes with the closing operation of the switch.

lt is an object of my invention to provide an improved electric switch of the fluid-break explosion chamber type which while retaining the circuit interrupting advantages thereof shall avoid the af'orenientioned circuit closing disadvantages thereof. A further object of my invention is to provide an improved construction of switch of this type wherein the insulating liquid is driven by the gas in a plurality ot streams into the arc at different portions thereof.

lily invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the' appended claims.

Referring to the drawing, Fig. 1 is a view partly in section of a portion of a fluid break .switch involving my invention and Fig. 2 shows a modification thereof.

I have illustrated my invention by way of example as applied to a switch of the type shown in the Huber Patent No. 1,546,175, July 11i, 1925. ln the drawing, the vessel 1 containing the insulating liquid 2 has the adapter or contact retainer 3 suspended therein by the insulator bushing l. Screw-threaded into the adapter 3 is the contact carrier 5 to which is attached the arcing ring 6 and within which is the lined contact 7. The lower portion oi the adapter is shown having a flange 8 from which depend the rods 9 1926. Serial No. 117,239.

which preferably are ol insulating material l'or supporting the enclosing or gas confining member 12 shown as an explosion chamber. rlhis chamber is illustrated as comprising a cylin der 13, a top plate 111 and a bottom plate 15, each ot insulating material, the top and bottom plates being provided with openings 16 and 1? respectively for the passage of the movable contact rod 18, relatively small clearance only being required around the rod. l have shown the supporting rods 9 secured in the plates 14 and 15 and in the flange 8 by means of the pins 19 but other means mayy be employed as required. The plates of the explosion chamber are further secured against displacement by the nut 20 on the lower end of each' rod 9 which engages the bottoni face of plate 15 and by the sleeve 21 on each rod between the top plate 14 and the flange 8. The chamber may, if desired, be of metal properly insulated as may be required for the current and voltage conditions of the circuit Ato be interrupted.

when the Contact rod 18 is withdrawn from the fixed contact 7 and below the open ing 16 in 'the top plate the pressure of gas in the chamber 12 resulting from the arc drawn therein and acting upon the end of the rod 18- accclerates the vopening movement of the switch. insulating liquid is first directed in stream from the upper opening 16 upwardly into the arc and as the rod 18 leaves the lower opening i7 a second stream of insulating liquid is directed therefrom downwardly into the arc. Hence two separate streams of insulating liquid are directed from the explosion chamber into the arc at two different portions thereof, thus 'facilitating the quenching of the arc. Upon closing the switch the potential difference between the contacts may cause an arc to strike between the contacts just prior to their engagement and if the load is very heavy at the instant of closing, considerable gas may be produce close to the fixed contact. fit-h the construction described, however, this Lgas is free to escape since the explosion chamber is removed from the bubble and the supporting rods offer but little resistance to its expansion. The opposing effect of the gas formation on the CTI.

the tubular member Fig. l.

closing movement of the switch is therefore negligible.

In the modiiication illustrated by Fig. 2 I have shown the enclosing or gas confining member as the tubular member 25. This member' is suitably secured as for example by the two nuts 26 threaded on the tubular member and engaging opposite sides of the supporting plate 27. Rods 28 suspend the plate 2T from the flange 8 o'l" the adapter 3 as in Fig. l, the remaining portion of the structure including the insulator bushing Ll, vessel l and insulating' liquid 2 as Well as the pins 19 and nuts 2O being also the same as in Fig. l.

In operation, the modified form illustrated by Fig'. 2 functions in a somewhat similar manner to that shown in Fig. 1. A certain amount of acceleration is given to the Contact rod 18 in opening by the pressure of gas in 25 and streams of insulating liquid are directed from opposite ends thereoivl into the are drawn between the contacts. In closing the switch the same advantages obtain as in the form illustrated by The Contact rod 18 after passing through the tubular member 25 comes Within striking distance of the i'iXed contact and the resulting gas bubble being free to expand laterally does not impede the closing movement ol" the switch.

What I claim as new and desire to secure by Letters Patent. of the United States, is,

fr iiuid break switch comprising a receptacle containing insulating' liquid, an insulator' .lmshing projecting into the liquid, a fixed member for said contact supported by said bushing, an explosion chamber, and a plurality of spaced rods securing said explosion chamber' to the flange of said member in spaced relation with said iXed contact, whereby said Contact may be removed Without disturbing the explosion chamber.

In Witness whereof, I have hereunto set my hand this 18th day of .I une, 1926.

JOHN D. HILLIARD.

contact.` a flanged retaining and enclosing 

